Separation Today Dewatering and Drying Technologies
Transcription
Separation Today Dewatering and Drying Technologies
Separation Today Dewatering and Drying Technologies for industrial and chemical Processes 02 SEPARATION TODAY 04–05 ANDRITZ fluid bed systems for the fertilizer industry 17 Centrifuges combined with hyperbaric filters or filter presses Increasing use of vegetable raw and waste materials (e.g. for alternative fuels like bio diesel, ethanol or for the generation of gas in biogas plants) means that the farmland has to be used intensively, especially in view of diminishing cultivation areas. An optimal solution for the dewatering of super-fine coal 06–07 Drying of Coking Coal in the Fluidised Bed In the 1980s, large-scale tests for drying raw coal for use in coking plants were performed in Germany, to increase performance of existing coke ovens. 18–19 ANDRITZ Universal Pressure Filter In 1975, Bird Machine Company, now a part of ANDRITZ Separation, Inc., sold the first Bird Young rotary filters for use in a terephthalic acid process. 20 Polymer and filtering aids, dewatering and more ANDRITZ is well experienced in systems involving fine coal, flue dust and sawdust. 08–11 ANDRITZ – Your System Supplier within the Process of Polymer Production Dewatering and drying from a single source 12–15 Steam pressure dewatering The efficient process for yielding a high DS-content in filter presses 16 ANDRITZ, the experts for solid/ liquid separation for applications in mineral processing Alone in processing plants for coal, 10 different types of dewatering sets are used. 21 ANDRITZ and sustainable development ANDRITZ is actively involved in sustainable growth projects in several markets and industries. 22 Our service offer for your machine ANDRITZ combines different centrifuge and filter press brands under one roof. 23 Our Centrifuge Service Our range of services for centrifuges includes everything from machine inspection to complete reconditioning of rotors, machines, gearboxes and hydraulic systems. ENVIRONMENT & PROCESS 03 50 years of experience and innovation ANDRITZ strengthens market leadership for sludge dewatering and drying The ANDRITZ GROUP is a global market leader for advanced technical plant, systems, and services for various industries (pulp and paper, steel, energy generation, dewatering and drying of sludges in environmental protection). The group is headquartered in Graz, Austria. With a staff of approx. 12,000 working in production sites, service and sales organizations all over the world, it is close to its customers. Complementary acquisitions, consistent inhouse developments and extension of the marketing network have been the gist of the ANDRITZ strategy in recent years. It has allowed offering new technologies and products for long-lasting customer success and brought average yearly sales increases of 14%. The ENVIRONMENT & PROCESS Business Area has been a major driver in this success story. It is considered as the supplier with the largest product portfolio for customized solid/ liquid separation solutions. Since the development of the belt press technology in the early 1970s, almost 50 years ago, ANDRITZ has been a major technology leader in the sector of sludge dewatering. Following the Sprout Bauer purchase in 1990, screens and sieves were integrated into the product portfolio, as were centrifuges (with the purchase of Guinard) and drum drying equipment (acquisition of TCW) in the early 1990s. The purchase of Swiss-based company 3Sys at the end of 2002 contributed the belt drying system to the ANDRITZ portfolio. With it, sludges can be dried using waste heat at around 100°C, virtually without primary energy. Later, a full concrete housing was developed, which reduces investment costs considerably. A total of three strategically important acquisitions marked the year 2004: the purchase of Bird machine provided ANDRITZ with a centrifuge range of up to 1,200 mm in diameter. In addition to the Bird and Humboldt centrifuges, the proven Rittershaus & Blecher filter presses also became part of the ANDRITZ product portfolio. A few months later, ANDRITZ bought the filtration business from Netzsch. This meant that it proceeded to market leadership for filter presses. The excellent sales organization of Netzsch filtration opened the important markets of South East Asia, South America and India. Sticky cakes, e.g. cakes resulting from drinking water treatment, can be processed on filter presses fully automatically thanks to the scraper mechanism that was developed by Netzsch and widely accepted by customers. At the end of 2004, the drying technology section of VA Tech Wabag in Ravensburg (formerly Escher Wyss and CT Umwelttechnik), a leading supplier of fluid bed systems for drying and cooling industrial bulk materials and municipal sludges, was taken over. Acquiring Lenser Filtration in 2005 was a logical step to further strengthen the ANDRITZ filtration know-how. Thus, ANDRITZ offers all technologically relevant filter press components from a single source. Lenser has remained an independent organization within the ANDRITZ GROUP, allowing it to retain its position as world leader in the supply of filter plates. In 2006, ANDRITZ signed the contract for the purchase of Contec Decanter Inc., California, USA. This has enabled ANDRITZ to add a further centrifuge and separator service cen- SALES FIGURES IN MEUR 2008 2007 2006 2005 ANDRITZ GROUP 3,610 3,283 2,710 1,744 ENVIRONMENT & PROCESS 366.6 364.5 366.5 289.2 tre on the American west coast to its already tight network of service organizations, and to strengthen its leading position in servicing centrifuge installations. The latest purchase was the centrifuge business from Decanter Pty Ltd, Australia, a company mainly active in the servicing of centrifuges, at the end of 2007. This move means that ANDRITZ can serve its customers on the Australian continent even better and more quickly. ENVIRONMENT & PROCESS has current sales of over 360 million EUR per annum, with sludge treatment accounting for some 50 per cent. The other half is contributed by different mechanical and thermal solid/liquid separation processes in the petrochemical, chemical, minerals handling and food industries. Record values were achieved over the past few years, especially in the centrifuge and filter press business. Over 450 centrifuges were manufactured and supplied for sludge dewatering alone. Nearly a third of sales is generated with spare parts, service and maintenance. 23 specialized service and repair centres form a complete and global after-market network. Each dewatering unit, each dryer type, is part of a comprehensive performance package. Whether belt presses, filter presses or centrifuges, belt, drum or fluid bed drying – customers will be offered the right ANDRITZ equipment for their requirements. Decades of experience and competence, customized technical solutions and the global presence through ANDRITZ service centres make ANDRITZ an attractive partner for sludge treatment, even for the most difficult tasks. WHEREVER YOU ARE LOCATED – ANDRITZ IS CLOSE TO YOU! 04 SEPARATION TODAY ANDRITZ fluid bed systems for the fertilizer industry Increasing use of vegetable raw and waste materials (e.g. for alternative fuels like bio diesel, ethanol or for the generation of gas in biogas plants) means that the farmland has to be used intensively, especially in view of diminishing cultivation areas. This requires specific fertilization to supply Example: potash fertilizer Once the raw material has been extract- the crops with nutrients and micro / trace Potassium is one of the three essen- ed, preparation takes place using different elements necessary for growth. tial plant nutrients besides nitrogen and processes and ANDRITZ fluid bed equip- phosphor. The annual worldwide con- ment. The fertilizers must have good transport sumption of potash (as KCl) totals about and storage properties and be easy to ap- 50 million tons. The raw material, potassi- ply on the farmland. um chloride, occurs usually together with other salts (e.g. halite) or magnesium- Fluid bed apparatuses made by ANDRITZ containing materials (e.g. carnallite) in ma- Fliessbett Systeme GmbH are used in nu- rine evaporates which were crystallised merous process steps of fertilizer produc- millions of years ago. Depending on the tion, as the following application example geological conditions, this salt mixture is shows: either mined or leached using water. Exhaust Air Fan Exhaust Air Cyclone Potash Salt Heater Gas Dryer Gas Fan Air Gas Burner Air Compacting Press Mill Sieve Sieve Water Cyclone Moisturizing Cooler Dryer Cooling Water Kristallines Produkt Gas Air Fan Air Cooler Compacted Product Air ENVIRONMENT & PROCESS 05 Stationary, all-metal, low-temperature fluid bed evaporation dryer/ cooler type DDC 1800 for granulated potash. Plant capacity 340,000 kg/h of granulated potash. Advantages of ANDRITZ fluid bed dryers / coolers for the potash industry: n all-metal construction which can be cleaned with water n suitable for high capacities (up to 720 t/h in a single appliance) n fast control response in case of process fluctuations Stationary, all-metal, high-temperature fluid bed dryer, type DDC 900, for hot gas temperatures of 650°C, for drying n dust-free final product due to aspiration of fines with exhaust air crystallised or potash separated by flotation. Further ANDRITZ fluid bed references for fertilizers: The production of potassium chloride (KCl) In many applications, and for better product mainly takes place by selective crystal- handling, the particle size of the potash fer- lisation using the so-called hot leaching tilizer is increased by compaction, crushing process or by crushing and separating the and screening to 2 to 4 mm particle size. crystals by flotation and subsequently dry- The sharp breaking edges generated by n ammonium sulphate ing the KCl-crystals in a high-temperature crushing are smoothed off by rewetting the n potassium nitrate fluid bed. particles in a rotating drum and afterwards n monopotassium phosphate moving and drying them in a fluid bed to n NPK and NP fertilizers Advantage: obtain a dust-free granulate which can be n urea prills and granulate Due to the high hot gas temperature, the easily handled. hot intake gas volume can be kept small and heat losses through the exhaust gas Drying of the granulate takes place in a flow can be reduced. stationary fluid bed using moderately warm air by evaporative cooling. The granulate is dried with a minimum of thermal energy input and simultaneously cooled. 06 SEPARATION TODAY Drying of Coking Coal in the Fluidised Bed In the 1980s, large-scale tests for drying raw coal for use in coking plants were performed in Germany, to increase performance of existing coke ovens. Wet Coal Testing was discontinued as the industry Sieve began to shift capacities to other coun- Cyclone Belt Dryer tries. Fluidbed Dryer Heat Transfer Medium Supply Asian coking plants habitually use a pre- Fan Heat Transfer Medium Reflux liminary drying process for the raw coal to moisture contents of approx. 5%. The shorter coking time and higher bulk den- Mixer Dry Coal sity of the dried versus the wet coal can Condensate from Medium Vapours increase oven productivity by as much as Heat Exchanger 15%. In the course of the German research Double Stage Coal Drying System projects, several drying processes were compared. Fluidised bed drying turned out to be the optimum technology. Thus, industry since 1963. In 1984, a fluidised maximum heat input on a small surface. the fluidised bed process is the method bed system was installed and operated This permits a compact plant layout. exclusively used to dry brown coal for successfully at Ruhrkohle AG’s research power plants. coking plant in Prosper. Line capacities of 500 t/h can easily be realised. But recently the predrying concept is be- Due to its physical properties (bulk den- ing reconsidered also in Europe. The rea- sity, particle size distribution) ground coke The exhaust steam from the dryer can be sons are the generally increased demand coal lends itself ideally to the fluidised bed used for heating purposes – comparable and the raw material shortage on the glo- process. to a multi stage evaporation plant. Due to the high inflammability of coal A considerable part of the heat input to In addition to increases in the coke oven dust, the dryer must be operated in a the fluidised bed dryer can be recovered capacity, environmental and quality as- closed steam loop. The absence of mov- with an upstream pre-dryer which oper- pects also play an important role. Oven ing parts at the dryer allows such an op- ates with exhaust vapours. temperatures can be lowered at given eration mode without sealing problems as capacities, which results in lower nitrogen they occur in drum dryers, for instance. Another ANDRITZ technology is also very oxide rates. The constant feed moisture The system’s oxygen concentration can suitable for pre-drying – the belt dryer. allows stable operation of the oven, plus be lowered to values which completely Both dryer types can be combined in a higher lifetime. The use of cheaper raw exclude the risk of dust explosions. highly efficient “DOUBLE DRY” system, bal market. coal with higher volatile portions results in economic benefits. ANDRITZ has produced fluidised bed dryers for all sections of the bulk handling which allows using heat several times and Use of tubular heat exchangers that are the utilization of energy in a modern, re- immersed in the fluidised layer allows sponsible manner. ENVIRONMENT & PROCESS 07 Drying of the waste from bioethanol production Drying of DDGS Wet Cake and Solubles Pump Steam Cyclone The fluidised bed system is operated in Fluidbed Dryer Fan Condensate Demister 120 °C Excess Vapour to Evaporator a closed vapour loop. The water evaporated in the dryer is discharged from the drying loop with a very low percentage of Scrubber inert gas in the form of overheated steam. The dew point of the excess vapours is Fliessbettkühler Dry Granules >90% TS higher than typically obtained from drum <40 °C DDGS Silo Fan dryers or steam tube dryers. The excess vapours are used as an energy source for the evaporator system of the thin stillage. ANDRITZ Fliessbett Systeme GmbH, Ravensburg offers the same drying proc- Drying of DDGS in closed Steam Loop Fluidbed ess for heating either with steam or natural gas. The type of fluid bed dryer is itself Bioethanol is the most important bio fuel the treatment of these by-product flows adapted according to the source of heat to date. Bioethanol is produced from glu- which had been used for more than 15 available. cose by the fermentation of yeast cells. years now for the drying of sludge from The glucose is primarily obtained from wastewater treatment. More than 25 in- 2nd generation bioethanol starch-containing plants such as corn stallations function worldwide using this Due to the competition between food and wheat or directly from sugar process- method. In our drying process, the filter and energy production, alternative ways ing. The proteins, minerals, fats and fi- cake and the concentrated stillage are of producing bioethanol are being devel- bres from the grain cannot be fermented initially coarsely mixed and transported di- oped. The next generation of bioethanol and are by-products from the process. A rectly into the dryer using regulated posi- installations will use cellulose as raw ma- high-quality animal feed, DDGS, can be tive displacement pumps. In the dryer, the terial. Cellulose is extracted from such obtained by drying the by-product. wet mixture is distributed and granulated waste material as straw, wheat stalks, by a special spreading/crushing device. corn stalks and leaves, or certain grass DDGS (Distiller’s Dried Grain with Solu- Otherwise large quantities of dried mate- species. By-products are also produced bles) is obtained from two material flows rial would have to be blended in. with these processes and have to be in the bioethanol factory. Firstly, the paste- dried. However, the residues do not con- like filter cake with the insoluble compo- A further advantage of this process lies tain ingredients suitable for animal feed. nents of the grain from the decanter cen- in the achievement of excellent bulk ma- Discussion on how these residues can trifuges, and secondly, the concentrated terial qualities in the dry granulate. With be dried and then incinerated to produce stillage with the soluble proteins, residual this process, pelletisation of the DDGS steam is still going on. sugar, etc., from the evaporator system. is no longer necessary. This reduces investment and operating costs as well as ANDRITZ Fliessbett Systeme GmbH, Ravensburg has adapted a process for maintenance requirements. 08 SEPARATION TODAY ANDRITZ – Your System Supplier within the Process of Polymer Production Dewatering and drying from a single source In many plastic production processes, the particles formed during polymerization are dewatered with centrifuges or rotary filters and then dried in a fluidized bed. Gastight solid bowl centrifuge HDPE According to our knowledge, ANDRITZ is Centrifuges and filters have become a suspension in a wide range from small the only manufacturer worldwide availing major tool in the wide range of chemical diameter up to 1.2 m for high capacities. on extensive references regarding dewa- and petrochemical applications. Espe- Some petrochemicals, especially tereph- tering and drying for a great number of cially in the suspension polymerisation thalic acid (CTA and PTA), as well as plastic materials. On that basis, ANDRITZ of monomers to form: polyolefins, poly- polyethylene and polypropylene require can offer both services from one single styrene, polyvinyls and terephthalic acids explosion proof gastight or pressure re- source. For you as the customer, the (HDPE, PVC, CTA, PTA). sistant machines at higher temperatures, number of interfaces to be coordinated which can be supplied by ANDRITZ. is reduced to a minimum. This advan- ANDRITZ supplies tailor made continu- tage has repeatedly been confirmed to ous solid bowl and screen bowl centri- us from our customers all over the world. fuges for dewatering of polymers from ENVIRONMENT & PROCESS ANDRITZ product range offers also single cell vacuum rotary filters, which are involved on the crude stage of terephthalic acid and pure stage, provide a maximum of efficiency and lowest possible energy consumption. ANDRITZ single cell filters offer higher speeds (higher filtration rates) due to no internal piping or an external distribution valve. The filter operates a much thinner cake and allows much higher wash efficiency then conventional rotary filters. With the successful development and operating experience of the single cell pressurised rotary filter incl. suitable let down device, ANDRITZ is able to ensure higher capacities with less separation equip- Testing facilities for centrifuges and filters ment, lower maintenance costs and less are available to optimize or develop new energy consumption on the PTA stage process together with our clients. with in the production process of terephthalic acid. The pressure filter reaches capacities up to 10.000 kg/m² filter area. System of Dewatering and Drying of Polymers Screen bowl Centrifuge gastight BPA Typical Flow diagram for Pressure filterr 09 10 SEPARATION TODAY Aside from the above mentioned sys- The VDC-type is preferably used for not Fluid bed systems of ANDRITZ are es- tems for the dewatering of polymers and easy fluidisable bulk material (high mois- pecially competitive for big line capaci- plastics ANDRITZ is supplying numerous ture, wide particle size distribution), the ties and huge dimensions of the equip- different systems for heating, drying, crys- DDC-type for low capacities and material ment.The biggest ever built fluid bed by tallization and cooling of polymers and with bigger particle size and the HDC- ANDRITZ is of effective working area of plastics based on fluid bed technology. type for high capacities and material with 100 m². The highest water evaporation smaller particle size. rate in one line is 12 t/h. So two in series essential arranged technology steps of the polymer production process can be supplied from ANDRITZ. This minimizes the interfaces for our clients in the system planning and installation phase. Wet PVC Cake Exhaust Air Fan Within the polymer production process Vibrating Disperser ANDRITZ is focused on the engineering and supply of continuous operating fluid Cyclone bed equipment and systems for mass Pump polymers, like e.g. PVC, HDPE, ABS, Heat Exchanger PMMA, PAA, POM, PP, PET, PTA, EPS and Adipic Acid. All system components are designed tai- Pump Hot Water Fluidbed Dryer Steam Dry PVC Powder lor-made to the requirements of the client which guarantees an optimum efficiency 1st Stage Air 2st Stage and lowest possible energy consumption. Every planned system can use different Scrubber Steam Air Filter Condensate Abb. 6 Drying of PVC in a Fluidbed Dryer fluid bed types for the drying of water or solvent containing polymers in open gas or inert closed gas loop systems, like shown in the tables 6 and 7. Cyclone Wet HDPE Cooling Medium Cyclone Hexane Scrubber/Condenser Steam Fan Fluidbed Dryer Condensate Dry HDPE Steam Fan Kreislaufgas Gas Heater Abb. 7 Drying of HDPE in a Fluidbed Dryer Condensate ENVIRONMENT & PROCESS 11 All fluid beds can be manufactured in different materials (including special alloy material) and adapted to the specific product requirements. The basic data for the design of the drying systems for new products will be investigated in our testing facilities and appropriate laboratories. Here together with the client new processes can be developed to allow a reliable scale-up to production size equipment. Fluid bed type HDC Fluid bed type VDC Fluid bed type DDC 12 SEPARATION TODAY Steam pressure dewatering The efficient process for yielding a high DS-content in filter presses Again and again, it is required to dewater sludges or residual matter to dry substance contents which, on one hand, cannot be yielded mechanically and, on the other hand, are not worth while the use of a drier considering the low evaporation rate. This is the field of application for a filter press with steam pressure dewatering combining the functions of mechanical dewatering and drying in one unit. Characteristic features : 1. During dewatering, no foreign steam is pressed into the bulk filling, but the steam cushion is exclusively generated from the residual moisture still contained in the bulk filling by heating it up. In practice, it was evidenced that a residual moisture of above 30% and below 80% best shows off the effect of steam pressure dewatering. 2. Due to it that a considerable part of the pore liquid contained in the bulk filling is pressed outwards by the steam cushion and must not be completely evaporated as in other processes, the steam pressure dewatering is an energy-saving and rapid dewatering process. 3. Due to their structure with restricted solids particles discretely embedded in the liquid phase, mineral sludges are excellently suited at a grain size distribution of d50 >30µm. 1 The theoretic fundamentals ther heat supply due to the increased The basic principle of steam pressure de- heat source, a heat sink in the form of a watering is based on a unilateral thermal drainage is generated. Thus, on its way to activation of a wet bulk filling. When the the heat sink, the steam cushion pushes boiling point of the liquid contained in the ahead the pore liquid still contained and bulk filling is exceeded, on the side where presses it off the bulk filling. the heat is introduced, a steam cushion is generated, which expands upon fur- pressure. On the side not showing to the ENVIRONMENT & PROCESS 13 2 The practical realization in filter presses A filter press converted for the steam 2.2 The filtering elements pressure dewatering process generally As regards the flowing properties, the fil- An ideal option to utilize this effect on a comprises the following: tering elements are designed such that large scale for dewatering and drying of they can rapidly discharge the vapors sludge of any kind is the chamber filter 1. The filter press frame generated during the end phase of steam press. Thanks to the filter chambers ar- 2. The filtering elements pressure dewatering. In practice, this ranged in series with a dept of 30 mm on 3. The heating elements means that the number of filtrate bores an average and to their spatial division, 4. The heating system is clearly higher compared with standard steam pressure dewatering effects can be 5. The suction device versions. The filtering elements are nor- realized in every filter chamber after a filter mally equipped with commercial heat- cake was concentrated in the filter cham- 2.1 The filter press frame bers by mechanical dewatering. ANDRITZ developed filter press frames resistant filter cloths. excellently meeting the requirements of 2.3 The heating elements The pre-condition for realizing steam a hot filter press. The side bar version as The pre-condition for the steam pressure pressure dewatering in filter presses is the well in the overhead version permit the dewatering effect is that within short time use of special heating elements permitting installation of the steam pressure dewa- sufficient heat is introduced into the layer a rapid and efficient introduction of heat. tering process. As the filter cakes do no of the filter cake directly adjacent to the These heating elements are combined more adhere upon high degrees of dry- heating surface. The steam cushion must with conventional filtering elements and ing and mostly fall off automatically when be built up and form a steam front which then provide the hot surface required for opening the filter press, the plate trans- then rapidly expands towards the cold the steam pressure dewatering effect and port systems developed by ANDRITZ side of the drainage. This is only possi- the opposite cool surface with drainage. permit the fully automatic operation of the ble with a well conducting heat exchanger filter presses. surface of aluminum alloys, stainless steels and, in special cases, also titanium. DDE Filterpress heating unit vacuum pump switch cabine plate package membrane squeezing system vapors filtrate sludge 14 SEPARATION TODAY To avoid that, immediately after having sure dewatering, the heating elements 3.2 Re-pressing been generated, the steam cushion be- are evacuated again and, thus, during the If the filter press should be equipped with comes relieved via the filtrate bores, the filtration proper, heating energy is not un- membrane filter elements, mechanical re- heating elements are generally not con- necessarily lost by heating medium left in pressing additionally increases the portion nected to the filtrate outlets. In this way, the heating elements. of dry substance in the filter cake. filter cake for escaping on the opposite 2.5 The suction system 3.3 Reduction of the viscosity side into the drainage of the filtering ele- As a considerable volume of vapors is Most of the heating energy is required in ments. generated during steam pressure de- the first ten minutes after the start of the the steam front is compelled to pass the watering, it is made sure that the vapor thermal activation for heating up the filter Generally, there are two types of heating leaves the filter chamber as soon as pos- cake. In the beginning, it is approximately plates for the steam pressure dewatering sible after having left the filter cloth without the four-fold of the quantity being with- process: the variant with the heating plate condensing on the cold drainage side of drawn from the filter cake after one hour completely made of metal and that with the filtering elements. To that end, suck- of heating up. To avoid that the heating the sandwich structure, where a plas- ing is recommended during the phase sets are selected disproportionally large, tic frame encloses a metal plate placed of steam pressure dewatering to, not at in most cases, a compromise between onto it. least, increase the efficiency. Sucking can supplied peak capacity and time is aimed be supplemented by a vapor condenser at. This means, the heating up phase is al- The advantage of the mere metal plate is connected before with following filter. If, ready started in the last five to ten minutes its extreme stability and its suitability for instead of saturated steam, water of 95°C of mechanic dewatering, irrespective of it, high temperatures, even beyond 200°C. should be used as heating medium, the whether this is the end of filtration or the sucking system helps to reduce the boil- re-pressing process. As a function of the Another option beyond the full-metal heat- ing point of the liquid in the filter cake by thermal conductivity and the heat storage ing plates is the light sandwich heating generating negative pressure in the filter- capacity, now, a more or less rapid heat- plate, which is fully heat-insulated towards ing chambers, until a steam cushion can ing up in the cake proper takes place. By the outside by the plastic frame and, to- form. the temperature increase, the viscosity wards the inside, directs the heat via the of the liquid in the filter cake is reduced 3 Process engineering – the complete cycle by up to two thirds. In this final phase of where it is needed. The sandwich heating plate is made of heat-resistant plastic The combined mechanical-thermal de- again which would not have happened material permitting heating temperatures watering method of steam pressure de- without heating up. In this way, consider- of up to 120°C in continuous operation. watering is sub-divided into at least one able volumes of filtrate are pressed off the mechanical part and a three-part thermal filter cake. placed-on metal plate exactly to the point mechanical dewatering, filtrate emerges 2.4 The heating system section. Despite the energy-saving drying, The only possible heating medium for the mechanical dewatering is approximately 3.4 The steam pressure phase sandwich heating plates is water of up to cheaper by the nine-fold related to the After the completion of the mechanic 95°C or saturated steam of up to 120°C. dewatering rate and the consumed en- phase during which the layers of the filter The full-metal heating plates can generally ergy and is, as before, the basis for steam cake directly adjacent to the heating plate also be operated with thermal oil and at pressure dewatering. have already been heated up, the pres- accordingly higher temperatures; how- sure in the filter chamber is very quickly ever, the use of oil as heating medium is 3.1 The filtration reduced to ambient pressure. In the al- not uncontested in many filter press ap- The filtration does not differ from the ready heated up layers, the liquid begins plications. former process adopted for chamber filter to change over to the state of bulk boiling presses. The feed pump forces the sludge where individual vapor bubbles are form- Compared with other heating media, the into the filter press with a previously set ing. With further energy supply, this vapor saturated steam has the decisive advan- maximal feeding pressure. cushion continues to expand and presses tage that, after the phase of steam pres- water into the direction of the drainage ENVIRONMENT & PROCESS DDE Cyclus 15 90 85 80 75 65 60 55 Solids Content 50 45 40 Solids Content 70 35 30 25 20 15 Re-Pressing 10 5 2h Filtration Drying Time and, hence, off the filter cake. Finally, af- heating plate, a best possible heat trans- These excellent characteristics are prov- ter a few minutes, the vapor breakdown fer via heat conduction up to the end of ing themselves every day in ANDRITZ takes place. The steam cushion proper drying. plants worldwide. A very good example in has reached the drainage of the filter this respect is the municipal sludge treat- plate and enters the filtrate outlets of the 4 Summary ment plant of the city of Brussels built filter plate. During the phase of the steam The steam pressure dewatering effect dis- by ANDRITZ - Separation and the steel pressure effect, up to 30% of the residual places the limits of the filter presses and works Acronin at Slovenia. moisture can be removed from the filter renders them full thermal driers after the cake. installation of the system and this without renouncing the advantages of mechani- Due to the incompressibility of the solids cal pre-dewatering. Where a further in- particles of the mineral sludges, a “clos- crease of the contents of dry substance est-possible ball packing” with free spac- in the filter cake is nor more possible with es results which favors the drainage. a further pressure increase, the phase of thermal activation begins. The filter press 3.5 The phase of contact drying equipped with heating plates initially de- The phase of contact drying is initiated by waters like a chamber filter press, repeats the steam break-through in the filter cake. pressing like a membrane filter press and Already in the steam pressure phase, the then dries like a thermal contact drier. In filter cake shrinks and sensibly looses vol- this way, the operator of the filter press ume. This tendency now becomes more can freely select the content of dry sub- and more intense. By an overpressure, stance in the filter cake. In most cases, which does not affect the evaporation of within a drying time of one hour, a dry the filter cakes, the membrane balances substance content between 80% and the volume decrease of the filter cake and 90% can be reached. permits, by pressing the cake against the 16 SEPARATION TODAY ANDRITZ, the experts for solid/liquid separation for applications in mineral processing Alone in processing plants for coal, 10 different types of dewatering sets are used. In the mining world, our name stands for: n Dewatering solutions of highest efficiency - maximal production at least possible costs n Centrifuges of any kind and with highest capacity of up to 450 t/h for large coal and of up to 120 t/h for the separation of fine coal n Wide product range for filter presses with highest capacities (side bar and overhead version) n Large belt presses of highest capacity and reliability n Rotary filters including the unique hyperbaric filter for up to 120 t/h and the AU- These are completely different centri- us to always find the most profitable solu- fuge types, chamber- and membrane fil- tion for you and your requirements – and filter with high speed ter presses, vacuum- and pressure disc this as a “neutral” consultant, since we of coal and other mining products, from filters as well as vacuum belt filters and can practially supply all dewatering sets the tests to the production unit, includ- screen belt presses. coming into question. n ing commissioning and service n Even if for certain applications only specif- Our close service network worldwide is a ic sets are coming into question, the fields further advantage we can offer. Extensive experience in the processing Tailor-made solutions for your individual requirements ping. For example, super-fine coal can be Not for no reason, we reached a leading dewatered with screen bowl centrifuges, position in the field of centrifuge and filter filter presses, disc filters or vacuum belt technology for the mining industry. We would like draw your attention to some of our references for the coal industry such as: filters, the investment and operating costs With pleasure together with our custom- n KWK Zofiowka - Poland as well as the dewatering results differing ers from the mining industry, we develop n Beresovskajy - Russia more or less strongly. new solutions for dewatering processes n Daliuta - China of application are more or less overlap- / dewatering tasks. Here, our sales and ANDRITZ Separation is an innovative service teams worldwide are in a dialogue high-tech enterprise in the field of sepa- with various experts, e.g. from the coal as well as for the copper and bauxite industry such as: ration engineering and its product range industry, engineering companies etc., to n Los Bronces - Chile comprises 9 of the machines mentioned find efficient and more profitable solutions. n Alunorte - Brazil above. Our extensive technical knowledge and our wide product range permit ENVIRONMENT & PROCESS 17 Centrifuges combined with hyperbaric filters or filter presses An optimal solution for the dewatering of super-fine coal Screen bowl centrifuges can dewater large solids volumes to high contents of dry substance. However, a fines loss results in particular in the screen area. To recover this material and return it to the yielded substance, it is recommended to adopt filtration technology, e.g. to use hyperbaric filters (HBF) or membrane filter presses. In this way, the moisture content of the super-fine coal can be reduced to less than 15% total moisture and a further process stage – that of thermal drying – can be omitted. In this way, the overall system yields an excellent filtrate quality without having to use additives such as flocculant etc. so that this filtrate can be reused as process The illustration (sketch) shows an overall With this super-fine coal, the dewatered water. capacity of the coal plant of 210 t DS/H end product has a total moisture of 17% split into approximately identical partial and the solids yield is above 99%. Instead flows to two screen bowl centrifuges and of continuously operated hyperbaric fil- two hyperbaric disc filters of 96 m . ters, also discontinuous membrane filter 2 presses could be used. Combined Technology Choices (SBC & HBF): 210 t DS/h 24,5% < 63µm Screen Bowl Centrifuge Advantages of the combination of technologies: Hyberbaric Filter 90 t DS/h 120 t DS/h 15.7 t DS/h 90 g DS/l 85% < 63µm 74.3 t DS/h 16.5% Product 208.3 t DS/h 17,5% 134 t DS/h 18% 375 t m3/h < 5g DS/l n Lowest moisture content n Filtrate without solids n Completely closed water circuit n Omission of the thermal process stage 18 SEPARATION TODAY ANDRITZ Universal Pressure Filter In 1975, Bird Machine Company, now a part of ANDRITZ Separation, Inc., sold the first Bird Young rotary filters for use in a terephthalic acid process. Prior to that time almost all of the terephthalic acid process used two stages of centrifugation, both in the crude step and then in the purified pressure step. AU-Filter A single Bird Young filter was able to re- The single cell rotary filter provides ficiency and lower cake moistures. Thin- place both stages of centrifuges in the unique advantages over conventional ner cakes also avoid cake cracking which crude step and the atmospheric centri- rotary vacuum filters: affects washing efficiency and leads to fuge in the pure step. Not only did the a. There is no internal piping or an external higher cake moistures Bird Young filter provide significant capital distribution valve that limits the speed of savings over the centrifuges but it also of- the filter, and therefore the filtration rate of c. The Bird Young filter can be equipped fered process advantages such as higher the filter. Practical experience shows the with a wash collection pan so that – if and solids recovery, lower cake moistures and filtration of the YU filter to be at least six to when necessary, the wash liquor can be improved product purity. Not to be forgot- seven times faster (higher) than a conven- reasonably isolated from the mother liquor. ten is the reduction in maintenance costs tional rotary vacuum filter. (see Figure 1). over high speed centrifugation. Faster filtration rates equal smaller filters With the success of the single cell, rotary and therefore smaller footprints and lower vacuum filter in the crude terephthalic acid installed costs. (CTA) separation step, the next challenge The Bird Young rotary filter was developed by Frank Young and differs from conven- was to apply the YU filter to the purified tional rotary drum filters in that it is of a b. The Bird Young filter operates with a terephthalic acid (PTA) pressure separa- single cell design rather than multiple fil- much thinner cake than a conventional tion step. This step requires separation of tration compartments. drum filter allowing for higher washing ef- the PTA from water at very high tempera- ENVIRONMENT & PROCESS tures (150-160ºC) and high pressures (5-6 bar g). The ability to make this separation is advantageous to the process as the impurities are kept in solution and can be removed by a product wash. However, to further enhance the process and to offer additional capital savings it was desired to also eliminate the second separation (atmospheric). To do this would require the pressure filter to discharge the solids under atmospheric conditions. Cake Thickness (oc Quantity Filtered) Q at high temperatures and high pressures Q CONVENTIONAL FILTER: Long Submergence Thick Cake Low Rate Q After years of reviewing and testing what t BIRD YOUNG: Short Submergence Thin Cake High Rate Filtration Rate = Slope dQ dt t was termed “pressure let down devices” ANDRITZ settled for a unique rotary valve that is able to discharge the solids that Submergence Time t are filtered at a pressure of approximately 5 – 6 bar g pressure to a screw feeder operating at atmospheric pressure. That a. Slurries can be pumped directly from screw feeder in turn feeds a dryer. the pressurized reactor to the filter, eliminating any precipitation of impurities The application of the ANDRITZ pressure which may have occurred under atmos- filter and the rotary valve eliminated two pheric conditions. stages of centrifugation and the interconnecting tanks, pumps, and piping, pro- b. The pressure filter is ideal where the viding considerable economic savings. In vapor pressure is high and where scaling addition, this combination has delivered may occur under vacuum conditions. a drier and higher purity product. Its performance has been proven in field tests c. The pressure filter allows for higher dif- with pilot scale equipment and in actual ferential pressures across the face of the installations. filter, enabling higher filtration rates and, in some cases, improved performance Pressure filtration with the ANDRITZ pressure filter offers the following ad- Pressure test filters are available for evalu- vantages, in addition to those listed ation on site and a wide range of sizes above, over conventional vacuum fil- ensures that we have a filter that will meet tration: your production needs. Cross Section high performance filter Typ HF 19 20 SEPARATION TODAY Polymer and filtering aids, dewatering and more ANDRITZ is well experienced in systems involving fine coal, flue dust and sawdust. Coal slurry dewatering is particularly at- Sawdust is of interest if the dewatered cake handling, and more important still, it pro- tractive when the dewatered sludge is to is to be composted, as the sawdust gives vides the necessary carbonaceous material be incinerated. The quantity of coal added sufficient body to the material to facilitate for optimum composting. can be adjusted in order that the right balance between improvement of filterability and the calorific value can be achieved and autogenous combustion of the dewatered cake can be enabled. Filterpress Fluidpicture ENVIRONMENT & PROCESS 21 ANDRITZ and sustainable development ANDRITZ is actively involved in sustainable growth projects in several markets and industries. Production of biofuels from cereals: ANDRITZ has strengthened its leading position as a preferred partner to European industrial companies for bioethanol plants. TEREOS, one of the largest global starch and sugar producers and the 4th largest ethanol producer worldwide, placed its Lillebonne, Normandy, plant in operation over a year ago. With seven ANDRITZ D7-series decanter centrifuges, the entire stillage is eliminated from the distillation columns. In this European production plant, TEREOS’ sustainability policy has yielded a 60% re- 2nd generation bioethanol: Biomass: duction in CO2 emissions and an energy Governments and industrial companies ANDRITZ has also supplied a large balance between 3 and 9, depending on across the world have launched research number of biomass drying plants. BDS, the raw materials and energy sources. and development projects and run pilot the new low-temperature belt dryer tech- plants to produce ethanol from cellulose nology, is particularly adequate for the Mastering the critical process stage, still- (“2nd generation ethanol”). These proc- drying of biomass used to produce fuel. age separation, has further strengthened esses use cellulose-rich materials such ANDRITZ’s leading position in ethanol pro- as straw or grass as feedstock. Before ANDRITZ, a leader in environmental tech- duction. A further wheat-based plant in fermentation, these plants break down nology, is also a preferred partner to many France, the largest European plant based the cellulose into fermentable sugars. industrial companies worldwide that have on wheat, corn or titricale in the United ANDRITZ is a technological leader in the made sustainability their goal and incor- Kingdom, and the first Asian plant not to handling of cellulose in the pulp industry porate it in their production process. use rice as feedstock will be equipped with and in solids/liquid separation, and thus ANDRITZ High Performance decanter cen- a natural and active partner in these de- trifuges. velopments. 22 SEPARATION TODAY Our service offer for your machine ANDRITZ combines different centrifuge and filter press brands under one roof, including the Bird Humboldt, ANDRITZ (formerly Guinard) and KHD centrifuges and the Rittershaus & Blecher and Netzsch filter presses for industrial and municipal applications. ANDRITZ offers a wide range of services for its own installed base (about 20,000 machines all over the world), and also for other brands. n High-level repair, reconditioning, rehabilitation and modernization n n Fast spare parts supply Competent plant maintenance and repair at the place of installation For you, this means n n 24 / 7 availability Use of service vehicles equipped with all necessary tools and spare parts n Experienced service partners with ISO 9001 quality standard n Highest standards and guaranteed reliability n Consultation by our expert personnel The ANDRITZ-Service-Network compris- sell, as well as AKW, BASF Ludwigshafen, n Regular maintenance and repair es 15 specialized repair workshops and BK Giulini, Clariant, Crimea Titan, DEC, Repair of rotors, gearboxes and eight locations with service technicians, Evonic / Degussa, EON, Filtratec, Hol- hydraulic systems on site so there is always one close at hand. The cim, Huntsman Tioxide, Infraserv, Kemira, n Storage of important specific spare parts Network includes the central production Norddeutsche Affinerie, Nyrstar / Umi- n Service contracts facilities with large repair workshops and core, RAG / Deutsche Steinkohle, RWE, n Diagnostic services, metrology spare parts supply as well as further re- Sachtleben, (e.g. endoscopy, frequency analysis) gional service centers. Over 500 rotor re- Ziemann, all in Germany … to name but n Plant optimization pairs per year speak for themselves. Our a few of the many renowned ANDRITZ n Modernization municipal clients include small townships customers. n Mobile plants, standby units (rotors and to big cities, which have entrusted us with screws) repair and servicing orders for many years. n Second-hand machines Examples are Singapore, New York, Bar- n Service trainings celona, Berlin and Vienna. n Repair documentation n Tailor-made engineering solutions n The industrial area covers a wide range of applications, the circle of ANDRITZ customers includes such companies as Omya worldwide, Reliance in India, LGP Korea, Sinopec Yhizeng in China, Anglocoal in South Africa, Soligorsk and Uralkaly in Russia; Bayer Lanxess, Wewatec, Kali& Salz, Deutsche Steinkohle AG, Ba- Thyssen-Krupp, Xstrata, ENVIRONMENT & PROCESS 23 Our Centrifuge Service Our range of services for centrifuges includes everything from machine inspection to complete reconditioning of rotors, machines, gearboxes and hydraulic systems. Apart from traditional maintenance, we can also modernize and optimize your centrifuge to achieve process improvements or more cost-efficient operation. Please contact us for further information regarding: nP otential capacity increases for your centrifuge, for example by the installation of a multiple screw conveyor. nM odernization of the oil circulation lubrication system n Improved operational safety with Backdrive Maindrive permanently oil-filled gearboxes thanks to filling level monitoring. n Special bowl linings as corrosion protection for bowls and machine casings made of standard steel. Mains Supply motor Backdrive Wear protection for the screw with ceramics and drum This includes (but is not limited to) improved wear protection for all surfaces subject to abrasion,such as the screw generator Backdrive Wear protection with ceramics inside Backdrive Old New = advantages 1 flow monitor = Oil quantity cannot be adjusted 2 flow monitors for 2 main bearings = oil quantity can be adjusted Oil pump is inside tank External oil pump = more easily accessible Pressure control valve inside tank External valve = more easily accessible Magnetic filter = machine must be stopped for cleaning Double filter = can be exchanged during operation Oil cooler mounted on base frame Oil cooler is part of the unit flights and the outer bowl. This protection is of particular importance for applications in the mineral and ore industry. Progressive optimization of the drive system would mean, for instance, conversion from hydraulic drive to electrical forward or backdrive using planetary or disc cam gears. Such a modification would save energy consumption and costs and increase environmental compatibility. EUROPE AUSTRIA ANDRITZ AG Contact Separation Technologies Phone: +43 316 6902 2318 Fax: +43 316 6902 463 e-mail: [email protected] Contact Thermal Process Technologies Phone: +43 316 6902 2990 Fax: +43 316 6902 453 e-mail: [email protected] GERMANY ANDRITZ Separation GmbH Phone: +49 221 9856 107 Fax: +49 221 9856 119 e-mail: [email protected] ANDRITZ Separation GmbH Phone: +49 9287 75 700 Fax: +49 9287 75 704 e-mail: [email protected] ANDRITZ Fliessbett Systeme GmbH Phone: +49 751 56058 0 Fax: +49 751 56058 920 e-mail: [email protected] Lenser Filtration GmbH & Co. KG Phone: +49 7307 8010 Fax: +49 7307 33 275 e-mail: [email protected] ENGLAND ANDRITZ Ltd. Phone: +44 1782 56 5656 Fax: +44 1782 56 6130 e-mail: [email protected] ANDRITZ Ltd. – Thermal Processes Phone: +44 1773 599 540 Fax: +44 1773 599 541 e-mail: [email protected] FRANCE ANDRITZ SAS Phone: +33 1 39 26 05 50 Fax: +33 1 39 26 05 60 e-mail: [email protected] NETHERLANDS ANDRITZ B.V. Phone: +31 2236 33474 Fax: +31 2236 37781 e-mail: [email protected] BRAZIL ANDRITZ Brasil Ltda. Phone: +55 11 2168 0130 Fax: +55 11 2168 0120 e-mail: [email protected] RUSSIA ANDRITZ Rep. Office Moscow Phone: +7 499 940 41 82 Fax: +7 499 940 41 86 e-mail: [email protected] ANDRITZ Separation Industria e Comércio de Equipamentos de Filtracao Ltda. Phone: +55 47 3387 9100 Fax: +55 47 3387 9104 e-mail: [email protected] RUMANIA ANDRITZ Rep. Office Bukarest Phone: +40 21 4304 166 Fax: +40 21 4304 166 e-mail: [email protected] ANDRITZ S.R.L., Romania Phone: +40 269 561 173 Fax: +40 269 561 727 e-mail: separation.ro-sibiu@andritz. com SLOVAKIA ANDRITZ Jochmann s.r.o. Phone: +421 53 4198 110 Fax: +421 534198 161 e-mail: [email protected] SPAIN ANDRITZ Ingenieria S.A., Madrid Phone: +34 91 663 64 09 Fax: +34 91 651 19 31 e-mail: [email protected] SWITZERLAND ANDRITZ 3Sys AG Phone: +41 56 618 46 80 Fax: +41 56 618 46 81 e-mail: [email protected] AUSTRALIA ANDRITZ Pty. Ltd. Phone: +61 38 795 9800 Fax: +61 39 799 4899 e-mail: [email protected] CANADA ANDRITZ Bird A Division of Andritz Ltd. , Saskatoon Phone: +1 306 931 0801 Fax: +1 306 931 2442 e-mail: [email protected] USA ANDRITZ Separation Inc., Walpole Phone: +1 508 404 1400 Fax: +1 508 668 6855 e-mail: [email protected] ANDRITZ Separation Inc., Houston 12734 Tanner Raod Houston, TX 77041 Phone: +1 713 856 1750 Fax: +1 713 856 1751 e-mail: [email protected] ANDRITZ Separation Inc., Lakeland Phone: +1 863 665 5811 Fax: +1 863 665 5851 e-mail: [email protected] ANDRITZ Separation Inc., Scott Depot Phone: +1 304 757 2678 Fax: +1 304 757 2689 e-mail: [email protected] ANDRITZ Separation Inc., Arlington Phone: +1 817 465 5611 Fax:+1 817 468 3961 e-mail: [email protected] CHINA ANDRITZ Technologies Ltd. Thermal Processes, Shanghai Phone: +86 21 5615 7190 Fax: +86 21 5615 7192 e-mail: [email protected] ANDRITZ Filtrationstechnik GmbH Office Shanghai Phone: +86 21 631 91 066 Fax: +86 21 631 91 068 e-mail: [email protected] ANDRITZ Technologies Ltd., Peking Phone: +86 10 5131 3700 Fax: +86 10 8230 6637 e-mail: [email protected] ANDRITZ Technologies Ltd., Foshan Phone: +86 757 8296 9222 Fax: +86 757 8296 9289 e-mail: [email protected] INDIA ANDRITZ Separation Private Limited Phone: +91 44 2615 3750/3751 Fax: +91 44 2615 4741 e-mail: [email protected] SINGAPORE ANDRITZ Singapore Pte Ltd. Phone: +65 6512 1800 Fax: +65 6863 4482 e-mail: [email protected] e-mail: [email protected] TAIWAN ANDRITZ AG Taiwan Representative Office Taipei Phone: +886 2 2722 7475 Fax: +886 2 2722 7476 e-mail: [email protected] SOUTH AFRICA ANDRITZ (Pty) Ltd Phone: +27 11 454 3350 Fax: +27 11 454 3381 e-mail: [email protected] Contec Decanter Inc. Phone: +1 510 614 1717 Fax: +1 510 614 1710 e-mail: [email protected] All data, information, statements, photographs and graphic illustrations made in this leaflet are without any obligation and raise no liabilities to or form part of any sales contracts of ANDRITZ AG or any affiliates for equipment and/or systems referred to herein. © ANDRITZ AG 2009. All rights reserved. No part of this copyrighted work may be reproduced, modified or distributed in any form or by any means, or stored in any database or retrieval system, without the prior written permission of ANDRITZ AG or its affiliates. Any such unauthorized use for any purpose is a violation of the relevant copyright laws. ANDRITZ AG, Stattegger Strasse 18, 8045 Graz, Austria ES.pp.01.eng.04.09